1. Technical Field
The present invention relates to a sensor device, an electronic apparatus, and the like having a pyroelectric element.
2. Background Technology
Infrared detection circuits in which pyroelectric elements or the like are employed are well-known. For example, infrared rays having wavelengths near 10 μm radiate from the human body, and detecting these rays allows information about the presence and temperature of a human body to be acquired without physical contact. Using such an infrared detection circuit therefore allows intrusion detection or measurements of physical quantities to be implemented.
The technologies disclosed in, for example, Non-Patent Document 1 and Patent Document 1 are well-known for infrared detection circuits. In the Non-Patent Document 1, a source follower circuit, which is configured from a transistor (JFET) and a resistor connected in series, is used to detect the pyroelectric current of a pyroelectric element.
In the Patent Document 1, a P-type transistor that functions as a load element and an N-type transistor that functions as an amplifier element are connected in series, whereby a common-source amplifier circuit is configured, and this common-source amplifier circuit is used to detect the pyroelectric current of a pyroelectric element.
Japanese Laid-open Patent Publication No. 2009-68863 (Patent Document 1) and Daisuke Akai et al., “Pyroelectric infrared sensors with fast response time and high sensitivity using epitaxial PbZr, TiO3 films on epitaxial γ-Al2O3/Si substrates.” Sensors and Actuators A: Physical, Volumes 130-131, 14 Aug. 2006, Pages 111-115, Elsevier Science B. V. (Non-Patent Document 1) are examples of the related art.